Garang died on July 30 when a Ugandan presidential helicopter on which he was travelling crashed on its way to south Sudan from Uganda, just three weeks after he became vice president under a landmark peace deal he helped craft.

His death raised fears about the peace process in the war-ravaged country and sparked deadly riots in Khartoum and towns in southern Sudan, with some southerners claiming the government may have had a hand in it.

Ugandan President Yoweri Museveni has suggested that the crash, initially blamed on bad weather in the mountainous region of south Sudan, may not have been an accident.

Sudanese President Omar al-Beshir issued a decree on August 8 establishing the seven-member committee and named former vice president Alier, a southerner who like Garang hails from the Dinka tribe, to head the panel.

The panel also includes six aviation experts — three from the Sudanese government and three from the former rebel group that Garang headed, the Sudan People’s Liberation Movement (SPLM).

Hamid told AFP the panel held a preliminary meeting late Saturday during which the SPLM team briefed their counterparts in Khartoum on the "measures that have been taken in the south since the crash."

"The committee has been given a month as of today (Sunday) to complete its mandate and submit its report to the presidency," Hamid said.

On the eve of Garang’s funeral, Museveni angered the Sudanese authorities with his suggestion that the crash of his presidential Russian-built helicopter may have been the result of foul play.

"Some people say accident, it may be an accident, it may be something else," Museveni told mourners in the southern town of Yei, where Garang’s had been brought ahead of his burial in Juba.

"The (helicopter) was very well equipped, this was my (helicopter) the one I am flying all the time, I am not ruling anything out," he said.

Sudan has said it will accept help from any country in its investigation and several countries, including the United States, Britain and the United Nations have offered assistance.

The US National Transportation Safety Board (NTSB) has dispatched a team of five experts, headed by senior NTSB investigator Dennis Jones, to help in the investigation. Jones has participated in investigations in Sudan twice previously

Hamid said one of the panel’s first tasks would be to visit the crash site in south Sudan and confer with US, Russian, Ugandan and Kenyan experts already involved in the investigation.